A code amber or yellow category would have given crews 19 minutes to attend to people suffering from chest pains, instead of the eight minutes they are allowed in a code red.

Ambulance staff said the changes would be the difference between life and death and when we alerted the Scottish Government , they immediately suspended them, saying the Chief Medical Officer had expressed concerns.

But 999 crews believe targets were being missed in the first place because of a lack of staff, with increasing numbers going off sick.

The ambulance service said they had “a range of measures that are rigorously applied to manage sickness absence”.